While Stan is out to pick up a few things one day, Lil’ Stinky notices Dipper use the copy machine to make some flyers, and is intrigued. After he leaves, the kitty sneaks into the room, and starts crawling around on the scanning surface, and pawing at the buttons. Somehow, he manages to make copy after copy of himself until the machine ends up breaking down from overuse.
Meanwhile in town, Stan is just exiting the grocery store, and suddenly notices that everywhere around him is dotted with little black puffballs in hoodies. Robbiekittens are lined up all over - perching on posts, mailboxes, and roofs, and just generally making everyone in town really uncomfortable. As Stan walks through, their little heads begin to pop up as all the kittens suddenly start focusing on him, and as he passes, they jump down from their various perches, and begin following him.
Soon enough, he has a massive herd of kittens behind him, all looking up at him and collectively purring. Stan tries to run from them, and quickly dashes into an alley, ducking behind a garbage can. He waits for the sound of purring to dissipate, and pokes his head out of the alley. The kittens are all gone. He exhales in relief, but as he turns to continue down the alley, he is greeted by the sight of hundreds of pairs of eyes glowing in the shadows as the rumble of their collective purring resumes.
No matter where he goes, the kittens follow. No matter where he hides, the kittens find him. Exhausted, he sits on the nearest available surface - a tree stump - and tries to catch his breath. The herd of kittens begins closing in, and Stan fearfully prepares himself for a fluffy assault. However, the hundreds of hairballs just quietly pile themselves around him, looking up at him with the same expression: OwO.
Stan eventually makes his way back to the Mystery Shack, and holds open the door as kittens begin piling inside en masse, all to the bewilderment of Dipper and Mabel, who are seated at the kitchen table, watching the house fill with fuzzballs. Completely worn out from trying to evade the army of floof, Stan deposits himself in his easy chair as kittens begin arranging themselves around him like a fuzzy game of Tetris: some by his feet, some on his lap, and one perched on the top of his fez. The twins find themselves knee-deep in sleeping, snoring kittens as Dipper tries to remember where Soos keeps the garden hose, knowing full well that the subsequent attack that will inevitably follow after drenching the real Lil’ Stinky is a sacrifice that must be made for the greater good.
(I sincerely apologize for how stupid this is)